Folding crutch



Feb. 3, 1970 I 2. R. BOYD 3,492,999

FOLDING CRUTCH Filed Nov. 20, 1968 3 Sheets-Sheet 1 INVENTOR.

I Z NE R. BOYD ATTORNEY z R. BOYD FOLDING CRUTCH Feb. 3, 1970 3 Shets-Sheet 2 Filed Nov. 20. 1968 INVENTOR.

ZANE R. aovo ATT NEY Z. R. BOYD FOLDING CRUTCH Feb. 3, 1970 3 Sheets-Sheet Filed Nov.

INVENTOR.

ZANE R. BOYD ATTORNEY United States Patent 3,492,999 FOLDING CRUTCH Zane R. Boyd, 9717 Par Lane, Wichita, Kans. 67212 Continuation-impart of application Ser. No. 706,962, Feb. 20, 1968. This application Nov. 20, 1968, Ser. No. 777,447

Int. Cl. A61h 3/02 US. Cl. 135-49 10 Claims ABSTRACT OF THE DISCLOSURE The invention is a foldable traveling crutch which occupies a limited space in a collapsed position. The crutch comprises an upper and lower section pivotally connected by a joint which also allows the sections to slide longitudinally with respect to each other when fully extended to a position locking the joint from pivotal movement.

This invention is a continuation-in-part to co-pending application Ser. No. 706,962 of Zane R. Boyd, filed Feb. 20, 1968, now Patent No. 3,447,632.

BACKGROUND OF INVENTION The conventional crutch used to assist the lame or infirm in walking, has gone substantially unchanged for many decades. While there have been some special use type crutches produced, the large majority on the market have been the conventional type which include a crosspiece at the end fitting under the armpit and a grip portion for the hand located approximately midway of its length. The length of these conventional crutches creates a space problem in all types of public and private transportation.

For example, when traveling in a car, they take up needed passenger space and in some of the smaller cars it is not possible to fit the crutches inside the car.

SUMMARY OF THE INVENTION The present invention is a full length lightweight metal crutch which compactly folds into two sections when not in use. The sections are connected by a joint which only allows them to fold when the two sections are pulled apart in a telescoping manner against a tension spring. The sections are likewise locked against pivotal movement only when the sections are fully extended in axial alignment with each other. When in the locked position the sectioned crutch provides a rigid structure capable of supporting any compressive and bending load which might be encountered.

It is therefore the primary object of the present invention to provide a high strength, lightweight foldable crutch which can be stored in a limited space.

It is an additional objective to provide an improved locking joint for a folding section crutch.

Further objects and advantages of the invention will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows and in which:

FIG. 1 is a front elevational view of the crutch in the extended position ready for use;

FIG. 2 is a side elevational view in the extended posi tion;

FIG. 3 is an exploded perspective view of the locking joint between the two sections of the crutch;

FIG. 4 is a side elevational view of the joint in partial section with the sections locked in the extended position;

FIG. 5 is a side elevational view of the joint with the sections in the folded position;

FIG. 6 is an exploded perspective view of a modified form of the locking joint;

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FIG. 7 is a side elevational view of the modified joint with the sections in the folded position; and

FIG. 8 is a side elevational view of the modified joint with the sections locked in the extended position.

Referring now to the drawings for a more detailed description of the invention, and more specifically to FIGS. 1 and 2, a foldable crutch is generally identified by the reference numeral 10. The crutch is made up of an upper section 12 and a lower section 14 connected by a pivotal locking joint 15. The lower section 14 includes a hollow tubular member 16 circumfusing a smaller member 18 in telescoping relation. Positioned on the lower end of member 18 is a common resilient non-slip foot 19. The tubular member 16 has a series of longitudinally spaced holes 20 through which a spring detent or other type locking means 22 can be adjustably positioned to vary the length of the crutch to fit persons of varying height. A shorter person would adjust the member 18 to the dotted line position illustrated in FIG. 1. The upper section 12 of the crutch is made up of two parallel spaced tubular members 24 joined at their upper ends by an arcuate-shaped shoulder rest 25. Laterally spaced between the members 24 is a hand grip 26. The lower ends of members 24 are anchored to the stationary member 28 of joint 15 while the upper end of tubular member 16 is anchored to the pivoting member 30 of the joint as will hereinafter be described in detail.

In FIG. 3 the two members 28 and 30 of the joint 15 are shown in an exploded detail view. The stationary member 28 has side portions 31 which girdle the ends of tubular members 24. The members 24 are anchored in place by rivots or other type fastening means through holes 32. Joining the two girdling side portions 31 is a web 33. Extending outwardly from one side of the web 33 are a pair of parallel spaced side walls 35 forming a channel to receive member 30. Passing traversely through both side walls 35 is a pivot pin 36 and a locking pin 37.

The pivoting member 30 of the joint 14 has a channelshaped cross-section and is anchored to the tubular member 16 (not shown in FIG. 3) by rivets or a similar type of fastening means through holes 38. Located in the web portion 40 of member 30 is an opening 41 for fastening the end of spring 42. Integral with web 40 are a pair of side walls 44 which make up the channel cross-section. The upper end of each wall 44 has a curved surface 45- with a diameter equal to the width of the side wall 44. The curved surface 45 is tangent to the web 40 and the outer edge 46 of the wall 44. Concentric with surface 45 is circular opening 47, which when the crutch is assembled, receives pivot pin 36 as seen in FIGS. 4 and 5. Intersecting the opening 47 is a slot 48 having a width approximate the radius of opening 47 with one edge of the slot tangent with said opening. Located inwardly from the end .of wall 44 is a second slot 50 longitudinally aligned with the first mentioned slot 48. One end of slot 50 has an opening 51 through the outer edge 46 of the wall. The distance A between either the pivot pin 36 or locking pin 37 and the web 33, as seen in FIG. 5, is less than half of the width of the wall 44. This restriction causes the pivoting axis of member 30 to move from side to side as member 30 is rotated from its FIG. 5 to its FIG. 4 position.

OPERATION When the crutch is in the extended locked position, as illustrated in FIGS. 2 and 4, a rigid joint without play is provided between the two sections. The outer edge 46 of the pivoting member 30 is held snugly against the web 33 of the stationary member by pins 36 and 37 positioned in their respective slots. Since locking pin 37 is out of alignment with opening 51 of slot 50, member 30 is locked against any pivotal movement about pin 36.

Pivotal movement is also prevented by the non-concentric position of pin 36 with respect to surface 45. Member 30 is held in this position by tension spring 42 urging member 30 upward so that the bottoms of slots 48 and 50 are in contact with pins 36 and 37. To unlock the lower section 14, member 30 is first pulled outward against the tension of spring 42. The two pins 36 and 37 will slide upward to the opposite ends of their respective slots 48 and 50. Pin 37 now being laterally disposed with respect to opening 50, the member 30 is free to rotate about pin 36. As member 30 rotates, pin 36 is forced to follow the edge of larger opening 47. This is caused by the limited space A between the pin 36 and the web 40 being approximately the same as the width of the side wall 44 between the opening 47 and the curved surface 45. When the lower section 14 of the crutch is completely folded, as shown in FIG. 5, the pivot pin 36 has moved to the opposite side of opening 47, out of alignment with slot 48. This prevents the pin 36 from riding up in slot 48 and locking the sections in the folded position. The crutch is therefore much easier to unfold.

FIGURES 6, 7 AND 8 In the previous embodiment just described, the upper and lower sections of the crutch, 12 and 14, are longitudinally offset from each other, as best seen in FIG. 2. The joint 15A of the present embodiment is so constructed that the sections are aligned with each other as shown in FIG. 8. The stationary member 52 of the joint comprises a web 58 joining two side portions 60 which girdle the ends of tubular members 24. Centrally disposed in web 58 is a recessed channel-shaped portion 54 having side walls 55. The two portions of the web 58 lie in separate planes, joining their respective side walls 55 at an acute angle. A slot 62 is provided in web 58 for the ingress and egress of pivot pin 36.

The pivotal member 53 of the joint has a channelshaped upper portion 64 with identical slots and openings 48, 50, 51 and 47, as previously described in FIG. 3. The lower portion 65 of member 53 receives tubular member 16 and is offset from the upper portion so that in the extended position the tubular members 16 in the lower section are longitudinally aligned with the tubula members 24 in the upper section (FIG. 8). When the crutch is in the folded position of FIG. 7, the tubular member 16 of the lower section is offset away from the tubular member 24 of the upper section so that the two sections can lie in parallel relation when in the folded position. The function of slots 48 and 50, and their related openings, are identical to those described in FIG. 3.

Having described the invention with sufficient clarity to enable those familiar with the art to construct and use it, I claim:

1. A foldable full length crutch comprising:

upper and lower sections (12, 14);

a pivotal locking joint (15) connecting the sections rncluding a stationary member (28) connected to the upper section and a pivoting member (30) connected to the lower section;

the stationary member having side walls joined by a web (33) forming a channel;

the pivoting member (30) positioned within the channel of the stationary member, having side walls (44) terminating at one end in a curved end surface (45);

a traverse arcuate opening (47) in the side walls (44) concentric with the curved end surface;

-a first traverse slot (48) in the side walls (44) extend ing from one end longitudinally into the arcuate opening offset from the longitudinal centerline of the slde walls (44);

a second traverse slot (50) in the side walls (44) extending longitudinally from one end toward the first slot, an opening (51) through an edge of the side walls (44) into the slot (50);

pivot means (36) for joining the two sections anchored laterally to the side walls (35) extending through the arcuate opening in the pivoting member allowing pivotal movement between the sections from an extended to a folded position as long as the pivot means does not enter the first slot (48);

locking means (37) anchored to the side walls (35) in alignment with the opening (51) when the sections are pivoted from the folded to the extended position; and

spring means (42) connecting the two sections urging the pivot means and locking means toward said ends of the respective first and second slots whereby the sections will slide longitudinally with respect to each other into a locked position.

2. A foldable full length crutch as set forth in claim 1 wherein, the upper section includes a pair of tubular members (24) held in parallel spaced apart relation by a shoulder rest (25) at the upper ends thereof and the stationary member (28) of the pivoting joint at the bottom ends with a hand grip (26) spaced therebetween; and the lower section includes a tubular member anchored to the pivoting member (30) at one end and a groundengaging foot at the opposite end.

3. A foldable full length crutch as set forth in claim 1 wherein, the upper section includes a pair of tubular members (24) held in parallel spaced apart relation by a shoulder rest (25) at the upper ends thereof and the stationary member (28) of the pivoting joint at the bottom ends with a hand grip (26) spaced therebetween; and the lower section including a first tubular member (16) anchored to the pivoting member of the joint, a second tubular member (18) held in telescoping relation with the first tubular member by an adjustable fastening means (22) so that the height of the crutch can be varied for the height of the user.

4. A foldable full length crutch as set forth in claim 1 wherein, the upper section includes a pair of tubular members (24), the stationary member of the joint having side portions (31) extending from each side of the channel, the tubular members being anchored to the side portions in a plane offset from the axis of rotation of the pivoting means (36).

5. A foldable full length crutch as set forth in claim 1 wherein, the upper section includes a pair of tubular members (24), the stationary member of the joint having side portions (31) extending from each side of the channel, the tubular members being anchored to the side portions in a plane offset from the axis of rotation of the pivoting means (36), the lower section includes a tubular member (16) anchored to the pivoting member (53) of the joint in an offset manner so that the tubular members of the upper and lower sections lie in the same longitudinal plane when in the extended position and are offset from each other in the folded position.

6. A foldable full length crutch as set forth in claim 1 wherein, the first and second traverse slots are longitudinally axially aligned with each other offset from the centerline of the side walls (44) toward the edge having the opening therein.

7. A foldable full length crutch as set forth in claim 1 wherein, the first and second traverse slots are offset from the longitudinal centerline of the side walls (44) toward the edge having the openings therein, the pivoting means (36) being spaced from the web (33) of the stationary member a distance substantially equal to the width of the side wall (44) between the first traverse slot and said edge of the side wall (44) whereby the said edge of the side wall is in contact with the web of the stationary member when the pivoting means is located in the first traverse slot.

8. A foldable full length crutch as set forth in claim 1 wherein, the first and second traverse slots are offset from the longitudinal centerline of the side walls (44) toward the edge having the opening therein, the width of the side wall (44) between the arcuate opening and the curved end surface being substantially uniform and equal to the width of the side wall (44) between the first traverse slot and said edge of the side wall (44).

9. A foldable full length crutch as set forth in claim 1 wherein, the first and second traverse slots are longitudinally axially aligned with each other offset from the centerline of the side walls (44) toward the edge having the opening therein, the pivoting means (36) being spaced from the web (33) of the stationary member a distance substantially equal to the width of the side wall (44) between the arcuate opening and the curved end surface whereby the curved end surface co-acts with the web (33) in a camming action to force the pivot means into the arcuate opening out of longitudinal alignment with slot 48 when the sections are rotated to the folded position.

6 10. A foldable full length crutch as set forth in claim 1 wherein, the arcuate opening is circular in shape with a diameter greater than the width of the first slot, with one edge of the first slot tangent to the arcuate opening.

References Cited UNITED STATES PATENTS J. KARL BELL, Primary Examiner 

